Easy opening containers



May 20, 1969 c. E. PALMER EASY OPENING CONTAINERS Filed Jan. 18, 1968 INVENTOR CHARLES E. PALMER BY ATTORNEY United States Patent US. Cl. 220-54 8 Claims ABSTRACT OF THE DISCLOSURE Easy opening containers constructed of tinplate are disclosed. The containers are opened along lines of weakness, provided in either their end closures or body Walls. Steel foil is bonded to the inside of the containers at least completely along the lines of weakness and the portions of the containers immediately adjacent thereto.

This invention relates to easy opening containers having portions thereof along which dispensing openings are located constructed of tinplate-steel foil composite materials.

The use of easy opening containers has become widespread. A typical easy opening container is provided with an end closure which includes a removable portion defined by lines of weakness provided therein and a pull member attached to the removable portion by means of which the removable portion is torn from the container. End closures of this type made of conventional tinplate are difi'icult to open, however, since tinplate is highly resistant to tearing even when the lines of weakness are provided by scoring the tinplate through as much as three-fourths of its thickness. Deeper scoring of the tinplate is not practical because the container end is then quite likely to rupture along the score lines if struck. In addition, the torn edge of the end closure is very sharp.

According to the present invention, easy opening containers are made from tinplate-steel foil composite materials. The tinplate forms the outside of the container and a removable portion is defined therein by score lines which extend through at least about 90% and preferably through the entire tinplate thickness. The steel foil is bonded to the tinplate so that it underlies the score lines.

Steel foil tears much more readily than an equivalent thickness of tinplate. Thus, it is easier to tear steel foil .002 inch thick than tinplate which has been scored down to that thickness. Consequently, the containers of the present invention can be opened without difficulty by means of a pull member attached to a removable portion defined by lines of weakness in said container end or body wall, since it is necessary to tear through only a maximum of about 10% of the tinplate thickness in addition to the steel foil thickness and preferably through the steel foil thickness alone. In addition, the opening in the tinplate formed as the container is torn open presents an edge against which the underlying steel foil is torn further aiding opening of the container. At the same time, the removable portion of the tinplate provides a protective bulk to the container during the shipping and general handling thereof.

An object of the invention is to provide easy opening containers having removable portions defining dispensing openings formed of tinplate-steel foil composite materials. Another object of the present invention is to pro vide such containers wherein the removable portions are defined by lines of weakness. A further object of the invention is to provide such containers where the lines of weakness are formed by scoring completely through the tinplate down to the underlying steel foil.

These and other objects and advantages of the present p CC invention will become apparent from the description thereof with reference to the accompanying drawing in which:

FIGURE 1 is a fragmentary top perspective view of a container having an end closure formed according to the present invention.

FIGURE 2 is an enlarged fragmentary vertical sectional view along line 2-2 of FIGURE 1.

FIGURE 3 is an enlarged fragmentary vertical sectional view similar to FIGURE 2 showing a modified form of end closure construction.

As an exemplary form of the present invention, the drawing shows a container 1 having a tubular body 2 and an end closure generally designated 3 secured thereto by means of a conventional double seam 4.

The end closure is formed from a composite material including an outer tinplate component 5 and an inner steel foil component 6 bonded together by means of a suitable adhesive 7. The tinplate typically has a thickness of about .008 inch and the steel foil a thickness of about .002 inch.

A circular line of weakness 8 concentric with and adjacent to body 2 is provided in the tinplate by scoring the tinplate through its entire thickness. The portion of the tinplate falling within the confines of the score line 8 comprises a removable section which is removed from the end closure along with the portion of the steel foil coextensive therewith to provide a dispensing opening in the container.

When the tinplate is scored completely through its thickness as shown in FIGURE 1, it is necessary to perform the scoring after the tinplate is bonded to the steel foil. However, where the score line extends only substantially completely through the tinplate, i.e., through at least about of its thickness, the score line may be made either before or after the tinplate and steel foil are bonded together.

Secured to the end closure by means of a suitable attaching device such as rivet 9, which extends through both the tinplate and steel foil, is an opening tab 10-. An opening 11 is provided in one end of the tab so that it can be firmly grasped thereat when the container is to be opened. The other end of the tab is provided with a downwardly inclined projection 12 which is positioned adjacent score line 8.

In opening the container, tab 10 is grasped at opening 11 and that end of the tab lifted upwardly causing the tab to pivot about rivet 9 forcing projection 12 downwardly so as to rupture the steel foil initiating a tear therein. The tab is then pulled away from the end closure detaching both the removable section of the tinplate and the steel foil bonded thereto from said closure. The steel foil tears away from the end closure along the edge of the opening formed in the tinplate thereby facilitating tearing of the steel foil. It can thus be seen that in opening the end closure described, it is necessary to tear through only the steel foil which is about .002 inch thick and because the resistance of steel foil to tearing is much less than that of tinplate scored to the same thickness, the container end can be opened with less difficulty than an end closure constructed of tinplate alone scored to within .002 inch of its entire thickness. At the same time the end closure is protected during shipping and general handling by the bulk provided by the removeable section of tinplate.

While it is desirable to provide large dispensing openings of the type illustrated in the drawing where the containers carry solid-like materials, the opening may take various shapes. For example, conventional tear dropshaped openings are used in conjunction with containers for liquids.

Containers are also provided having removable portions defining dispensing openings along the container body wall. Thus, for example, a tear strip is defined about the circumference of a container constructed of tinplate by a pair of parallel score lines extending through at least 90% of the tinplate thickness. Bonded to the inside of the container completely underlying the score lines is a steel foil strip of a width somewhat greater than that of the tear strip.

The use of steel foil having a thickness of about .002 inch is preferred since steel foil of that thickness or less is especially easy to tear. Steel foil of a heavier gauge is used however. The steel foil employed can have any temper although generally full hard steel foil is used. Full hard steel foil is foil which has not been annealed after having :been worked to final gauge.

FIGURE 3 illustrates a modification of the embodiment shown in FIGURES 1 and 2 in that the steel foil component rather than being coextensive with tinplate component 5 is in the shape of an annulus 13 and underlies only the scoreline -8 and portions of the tinplate immediately adjacent thereto.

While presently preferred embodiments of the invention have been described and illustrated herein, it is to be understood that changes and variations may be made by those skilled in the art Without departing from the spirit and scope of the appended claims.

I claim:

1. An easy opening container constructed of tinplate, lines of weakness in said tinplate defining a removable portion therein, said lines of weakness extending at least through 90% of the thickness of said tinplate, steel foil bonded to and underlying said tinplate at least completely along said lines of weakness and the portions of the tinplate immediately adjacent thereto, and tab means secured to said removable portion for tearing open the container along said lines of weakness.

2. A container as defined in claim 1 wherein the lines of weakness extend completely through the tinplate.

3. A container as defined in claim 1 wherein the steel foil is about .002 inch thick.

4. An container as defined in claim 3' wherein the steel foil is full hard.

5. A container as defined in claim 2 wherein the lines of weakness are in the container end closure.

6. A container as defined in claim 5 wherein the removable portion defined by said lines of weakness extends over substantially the entire end closure.

7. A container as defined in claim 6 wherein-said tab means is secured to said removable portion intermediate its two ends, one end of said tab means including a downwardly inclined projection positioned adjacent the lines of weakness, said projection acting downwardly to initiate a tear in the steel foil upon raising of the other end of the tab means.

8. A container as defined in claim 1 wherein said steel foil is in the shape of an annulus.

References Cited UNITED STATES PATENTS 3,089,609 5/1963 DAndrea 220-54 GEORGE T. HALL, Primary Examiner. 

